Isolation and purification of an antibody to 67-KD calcimedin

The 67-KD calcimedin is a calcium-binding protein isolated from several muscle tissues. The protein shows apparent Mr of 67,000 by SDS-polyacrylamide gel electrophoresis. An antibody has been prepared by immunizing sheep with the protein purified from chicken gizzard smooth muscle. This antibody recognizes 67-KD calcimedin but not calmodulin, bovine serum albumin, transferrin, or brain p68 calelectrin. The presence of 67-KD calcimedin is demonstrated in the smooth muscle cell lines A10 and DDT1MF-2 as well as in primary cultures of chicken breast and heart muscle, by immunoprecipitation and immunofluorescence. The 67-KD calcimedin, being responsive to calcium, may play a role in calcium-mediated cell regulation. This report identifies several cells that may be useful for further delineation of the cellular role of 67-KD calcimedin.